If you're like most Americans, bread, pasta, soft drinks, French fries, sugar, and similar foods probably flew into your mind. Yes, these foods are carbs -- highly processed and refined ones.

And if these are the kinds of carbs you consume on a regular basis, let me warn you, (unless you regularly run marathons), you're most likely either overweight or heading down the road to weight gain.

You may like them, you may consider them "comfort foods," you may think that they couldn't be so bad since they are so predominant in our current diet. But the biological bottom line is that human beings have not evolved to metabolize these types of carbohydrates.

They slow down your metabolism and contribute to every one of the major diseases associated with aging including diabetes, heart disease, dementia and cancer.

In most, cases they are also "empty" calorie foods-the worst possible combination -- high caloric foods, low in nutrients. They deprive you of vital nutrients as well as burden your body with the task of digesting food molecules that aren't giving you anything you need.

Eating them (especially in excess) is a prescription for weight gain. But they're not the end of the carb story. If you're like most people, you may not realize that the wide world of carbs is actually much, much bigger than this limited crowd of processed carbs.

So you have a choice: use phytonutrients to spark your metabolism into action, or drown your metabolism with indigestible nutrient-poor carbs.

Our genetic nutritional template goes back 20,000 years. Our ancestors foraged for wild food, like wild berries, grasses, roots, and mushrooms to find life-giving phytonutrients that all humans are designed by nature to eat.

On a recent vacation I found myself in a sea of phytonutrients in the wild islands of Southeast Alaska. I was foraging along with the grizzly bears for bog cranberries, blueberries, nagoonberries, raspberries, and strawberries. These scrumptious berries, bursting with phytonutrients, were smaller, richer in color and taste, (and lower in sugar) than their domestic berry cousins.

Here's a tip: The greater variety and the deeper the color of plant foods you eat, the higher their concentration of phytonutrients. The key is to learn which phytonutrient-dense foods can prevent disease and promote weight loss.

Want phytonutrient power?

Here 's a small sample of the many superfoods that contain these powerful phytonutrients: isoflavones in soy foods, lignans in flax seeds, catechins in green tea, polyphenols in cocoa (yes, chocolate!), glucosinolates in broccoli, carnosol in rosemary, and resveratrol in red wine.

And there are hundreds more that can help you unlock the secret to natural weight loss. All of these compounds -- and dozens more -- will help you fight disease and obesity. These special compounds literally communicate with your genes and turn on messages of health and weight loss. They are key to the success people experience in losing weight on a program I've developed during my 20-years practicing medicine, called UltraMetabolism.

Before you reach for that Cinnabon, know that phytonutrients only occur in whole, unrefined, unprocessed plant foods. All vegetables (and many fruits) score high in phytonutrients, while processed carbs, like bread and pasta, have virtually none.

Here's a shorthand to distinguish between the metabolism boosters and the processed carbs that will only weigh you down:

Anything that has been packaged or put through a machine is processed (like a potato chip). Anything that comes right out of the earth is natural (like a plum).

Don't let all the terminology -- high fat, low-fat, high-carb, low-carb, high glycemic index, low glycemic index, complex carbs and simple carbs -- confuse you. The key is eating whole, real, unprocessed, food found as close to nature as possible. Now you know why your grandmother always told you to eat your vegetables!

Folk wisdom passed down the generations showed how to give the body what it needs. In the early twenty-first century, that wisdom is being confirmed in the research of leading edge scientists. So you can follow these recommendations I offer with total confidence that the latest medical science backs them up.

This new science reveals why you should never do what some ill-advised diets suggest: cut out all carbs. Not a good idea-because you also cut out all the phytonutrients (and the fiber) that only comes from whole plant foods.

Along with their obesity fighting chemicals, vitamins, and minerals to accelerate your metabolism, most whole carbohydrates are filled with healthy plant fiber to slow the absorption of sugar into your bloodstream.

And for super fast weight loss, you'll want to eat some special "super" fiber foods which I use as my secret weapon with many patients who have had difficulty losing weight. Once you incorporate them into your diet, you'll feel full, experience steady energy, and will never be tempted to overeat.

Here's a guarantee: If you've been consuming highly processed foods such as sodas, chips, and crackers, and you decide to boost your intake of those powerful phytonutrients that I've reviewed, you'll be taking the first step towards re-programming your body for automatic weight loss and health.

My dirty little secret as a doctor is that I never treat anybody specifically to lose weight; I simply help them become healthy using these and other techniques and the weight automatically comes off.

So remember, eat your carbs, but make them the right carbs!

About the Author:

Mark Hyman, M.D. is a NY Times bestselling author, lecturer, and practicing physician. Discover how you can program your body to automatically lose weight and find out what special super fiber can help by grabbing an exclusive sneak preview of UltraMetabolism at http://www.ultrametabolism.com/article6.